Britain and Russia both decide that a war between Germany and France is non of their affair. Consequently, neither go to war in support of France in 1914. Facing the combined might of Germany and Austria/Hungary, (with no threat to the east for those powers) France falls by 1916 at the latest. The terms of surrender are that Germany takes over the French Empire in West Africa and Indochina--all French colonies go under German control.
Therefore...
No collapse of the Romanov, Hohenzollen or Hapsburg Empires;
British Empire remains strong and suppresses revolt, while gradually allowing statehood for various groups
No Soviet Union
No Depression (at least, not for the reason it occurred on OTL)
No Hungry Thirties, no rise of Hitler
No WW2
No Iron Curtain or Warsaw Pact
Therefore...
No collapse of the Romanov, Hohenzollen or Hapsburg Empires;
British Empire remains strong and suppresses revolt, while gradually allowing statehood for various groups
No Soviet Union
No Depression (at least, not for the reason it occurred on OTL)
No Hungry Thirties, no rise of Hitler
No WW2
No Iron Curtain or Warsaw Pact